Epithelial Tissues

• Epithelial tissues consists of SHEETS CELLS that functions as what?(3)

  Covering, absorption, and secretion
• All epithelia are considered as what?

  Avascular
• Avascular: No blood supply, no oxygen, no nutrients, no waste removal
• Cells in the epithelial tissues are what?

  Polarized
• Epithelial cells have an APICAL and BASAL poles.
• Apical: top
• Basal: bottom
• The basal surface of all epithelia rests on a thin extracellular, felt-like sheet of macromolecules known as what?

  Basement membrane
• Basement membrane: semipermeable filter for substances reaching epithelial cells from below
• Basal lamina: denotes the fine extracellular layer seen ultrastructurally
• Basement membrane is visible with what type of microscope?

  Light microscope
• What are the 2 layers of basement membrane?

  Basal lamina and reticular lamina
• What layer of basement membrane is IMMEDIAELY beneath the epithelial cells?

  Basal lamina
• How thick is the basal lamina?

  20-100 nm
• Basal lamina consists of a network of what?

  Fine fibrils
• What layer of basement membrane is MORE DIFFUSE and FIBROUS?

  Reticular lamina
• What type of epithelial tissue is found in the PCT?

  Simple cuboidal
• What type of epithelial tissue is found in the capillaries?

  Simple squamous
• What type of epithelial tissue is found in the Bowman's capsule?

  Simple squamous